It is well known that portable electronic devices—such as laptops computers, personal digital assistants (PDAs), cell phones and the like—are subject to extensive movements and, many times, to inadvertent drops and other unexpected impacts. This can cause damage to the portable electronic device. This is especially true for electronic devices, such as laptop computers, having hard disks or hard drives. A hard disk (commonly known as a HDD (hard disk drive) or hard drive (HD) and formerly known as a fixed disk) is a non-volatile storage device which stores digitally encoded data on rapidly rotating platters with magnetic surfaces. Hard disks were originally developed for use with computers. In the 21st century, applications for hard disks have expanded beyond computers to include digital video recorders, digital audio players, personal digital assistants, and digital cameras. In 2005, the first mobile phones to include hard disks were introduced by Samsung Group and Nokia. Hard disks record data by magnetizing a magnetic material in a pattern that represents the data. They read the data back by detecting the magnetization of the material. A typical hard disk design consists of a spindle which holds one or more flat circular disks called platters, onto which the data is recorded. The platters are made from a non-magnetic material, usually glass or aluminum, and are coated with a thin layer of magnetic material. The platters are spun at very high speeds. Information is written to a platter as it rotates past mechanisms called read-and-write heads that fly very close over the magnetic surface. The read-and-write head is used to detect and modify the magnetization of the material immediately under it. There is one head for each magnetic platter surface on the spindle, mounted on a common arm. An actuator arm (or access arm) moves the heads on an arc (roughly radially) across the platters as they spin, allowing each head to access almost the entire surface of the platter as it spins. The hard disk's read-write heads fly on an air bearing which is a cushion of air only nanometers above the disk surface.
Due to the close proximity of the read-write heads to the disk surface, it can be seen how easily the disk may be damaged by the read-write head if the device is dropped or moved rapidly and suddenly while the read-write head is performing an action on the disk. For example, a laptop user may be using his/her laptop computer on his/her lap and may inadvertently drop the laptop to the floor causing an impact to the laptop. Because the laptop was in use at the time of the drop, the read-write head is most likely to be in a position in close proximity to the disk at the time of impact causing the read-write head to impact the disk and, many times, causing fatal damage to the disk so that the data on the disk is not recoverable.
Computer manufacturers have taken steps to help resolve this problem. For example, IBM created a technology for their ThinkPad® line of laptop computers called the Active Protection System. When a sudden, sharp movement is detected by a built-in motion sensor, such as a triaxial accelerometer, in the ThinkPad laptop, internal hard disk heads automatically unload themselves into a parking zone (i.e., an area of the disk where no data is stored) to reduce the risk of any potential data loss or scratches made. (An accelerometer is an instrument for measuring acceleration, detecting and measuring vibrations, or for measuring acceleration due to gravity (inclination). A triaxial accelerometer is an accelerometer which can detect acceleration along all three axes.) Apple later also utilized this technology in their Powerbook, iBook, MacBook Pro, and MacBook line, known as the Sudden Motion Sensor.
These types of systems detect sudden dramatic changes of acceleration—such as when the laptop or other electronic device is dropped—and performs some protective action on the electronic device, such as parking the read-write head(s) or even deploying shock absorbers on the laptop or other electronic device. (E.g., shock absorbers may be deployed from the corners of the laptop (on which the laptop is likely to land) to damper the sudden shock of impact and dissipate the kinetic energy built up from the fall.) These types of systems can be effective for drops from the user's lap, for instance.
However, because these systems are designed to protect the device based upon impact primarily from a drop, i.e., gravity is the force causing the change in acceleration, the system is designed to identify sudden dramatic changes in acceleration, such as going from a zero acceleration to the acceleration of gravity, or 9.8 m/s2 (32 ft/s2). Designers of such systems choose not to lower the predetermined acceleration change threshold as, many times, laptops or other electronic devices are, for instance, intentionally moved from one spot to another. It would be undesirable to the user for the system to automatically shut down or have the disk self-park for such safe activities as this.
Because most systems are designed to protect laptops and other devices from impact as a result of free fall, the systems are basically designed to perform the protective action when the acceleration rate approaches the acceleration rate of gravity. However, there are times when another force, as opposed to gravity, causes the change in acceleration and resulting potentially damaging impact to the laptop or other device such that the systems of the prior art do not have time to perform the protective action such as parking the read-write head. For instance, a user may be having some troubles with his laptop and, out of frustration, shakes or even bangs the laptop. It may be that the movement from such a user shake or bang is so sudden that the protective systems of the prior art don't have time to protect the device from damage. However, many times, it may be predicted when a sudden violent movement is to happen. That is, when a user is having troubles with his laptop, his level of frustration may gradually increase and, likewise, the level of violence of his shakes or bangs may likewise increase until the level has reached a point where damage may be done to one or more laptop components. It would be desirable for a system to have the ability to predict a sudden violent physical movement by detecting patterns of low level physical movements indicative of a possible sudden violent movement and to take precautionary protective measures when such patterns are detected.
Furthermore, present systems only provide protection to one component—the hard disk. So, even if the systems of the prior art are able to protect the hard disk from the violent physical movement, other components of the portable electronic device may be subject to damage. It would be desirable for a system to protect other components—possibly selected based upon the level of violence of the physical movement or patterns of detected physical movement.
Furthermore, many components of various electronic devices may be damaged, not only by a single violent physical movement or impact, but through a cumulative effect of numerous physical movements. An example of this could be the frustrated user described above who continuously shakes his computer but, in this case, never reaching a level of violence high enough to reach the threshold to trigger the systems of the prior art to take protective measures. It would be desirable for a system to protect components which may become damaged due to cumulative physical movements by detecting a series of physical movements and taking protective measures based upon the detection of pre-specified patterns of physical movement.
Present systems can provide audio or visual feedback to the user based upon a percussive impact, as well as performing a full shutdown to limit further damage. But, such systems provide such feedback based upon a single impact rather than a series of impacts or a series of movements. It would be desirable for a system to be able to detect a series of movements or impacts and take action based upon the type and amount of such series of movements or impacts.
In view of the foregoing, a need exists to overcome these problems by providing a system and method for detecting and protecting a portable electronic device when pre-specified shake patterns and levels are detected.